Multifunctional charger system and method

ABSTRACT

An adapter for providing a source of power to a mobile device through an industry standard port is provided. In accordance with one aspect of the invention, the adapter comprises a plug unit, a power converter, a primary connector, and an identification subsystem. The plug unit is operative to couple the adapter to a power socket and operative to receive energy from the power socket. The power converter is electrically coupled to the plug unit and is operable to regulate the received energy from the power socket and to output a power requirement to the mobile device. The primary connector is electrically coupled to the power converter and is operative to couple to the mobile device and to deliver the outputted power requirement to the mobile device. The identification subsystem is electrically coupled to the primary connector and is operative to provide an identification signal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. patent application Ser. No.12/905,934, filed Oct. 15, 2010 now U.S. Pat. No. 7,986,127, by DanielM. Fischer, et al. and entitled “Multifunctional Charger System andMethod,” which is a continuation of U.S. patent application Ser. No.12/714,204, filed Feb. 26, 2010 now U.S. Pat. No. 7,834,586, by DanielM. Fischer, et al. and entitled “Multifunctional Charger System andMethod,” which is a continuation of U.S. patent application Ser. No.12/268,297, filed Nov. 10, 2008, now U.S. Pat. No. 7,737,657 issued onJun. 15, 2010, by Daniel M. Fischer, et al. and entitled “System andMethod for Charging a Battery in a Mobile Device,” which is acontinuation of U.S. patent application Ser. No. 11/749,680, filed May16, 2007, now U.S. Pat. No. 7,453,233 issued on Nov. 18, 2008, by DanielM. Fischer, et al. and entitled “Adapter System and Method for Poweringa Device,” which is a continuation of U.S. patent application Ser. No.11/175,885, filed on Jul. 6, 2005, now U.S. Pat. No. 7,239,111 issued onJul. 3, 2007, by Daniel M. Fischer, et al. and entitled “UniversalSerial Bus Adapter for a Mobile Device,” which is a continuation of U.S.patent application Ser. No. 10/087,629, filed Mar. 1, 2002, now U.S.Pat. No. 6,936,936 issued on Aug. 30, 2006, by Daniel M. Fischer, et al.and entitled “Multifunctional Charger System and Method,” which claimspriority from U.S. Provisional Application No. 60/273,021, filed Mar. 1,2001, by Daniel M. Fischer, et al. and entitled “System and Method forAdapting a USB to Provide Power for Charging a Mobile Device” and U.S.Provisional Application No. 60/330,486, filed Oct. 23, 2001, by DanielM. Fischer, et al. and entitled “Multifunctional Charger System andMethod.” Each of the above patent applications is hereby incorporatedherein by reference in its entirety for all purposes.

BACKGROUND

This invention relates generally to power adapters. More particularly,the invention relates to power adapters for use with mobile devices.

Providing an external source of power to a mobile device, such as apersonal digital assistant (“PDA”), mobile communication device,cellular phone, wireless two-way e-mail communication device, andothers, requires design considerations with respect to both the mobiledevice and the power source. With regard to the mobile device, mostmobile devices provide a distinct power interface for receiving powerfrom a power source, for instance to recharge a battery, and a separatedata interface for communicating. For example, many mobile devicespresently use USB (Universal Serial Bus) interfaces for communicatingand use a separate power interface, such as a barrel connector, forreceiving power.

It is desirable, however, to have a combined power and data interface.The mobile devices that do have combined power and data interfacestypically use non-standard and sometimes proprietary interfaces.Consequently, combined interfaces for a particular manufacturer's mobiledevice may not be compatible with combined interfaces for mobile devicesprovided by other manufacturers.

Although the USB interface can be used as a power interface, the USB istypically not used for that purpose by mobile devices. In accordancewith the USB specification, typical USB power source devices, such ashubs and hosts, require that a USB device participate in ahost-initiated process called enumeration in order to be compliant withthe current USB specification in drawing power from the USB interface.Although a mobile device could be adapted to participate in enumerationwhen drawing power over the USB interface, it would be preferable inmany situations, such as when a host would not be available, as oftenhappens during normal use of a mobile device, to be able to utilizealternate power sources such as conventional AC outlets and DC carsockets that are not capable of participating in enumeration to supplypower to the mobile device via a USB interface.

SUMMARY

An adapter for providing a source of power to a mobile device through anindustry standard port is provided. In accordance with one aspect of theinvention, the adapter comprises a plug unit, a power converter, aprimary connector, and an identification subsystem. The plug unit isoperative to couple the adapter to a power socket and operative toreceive energy from the power socket. The power converter iselectrically coupled to the plug unit and is operable to regulate thereceived energy from the power socket and to output a power requirementto the mobile device. The primary connector is electrically coupled tothe power converter and is operative to couple to the mobile device andto deliver the outputted power requirement to the mobile device. Theidentification subsystem is electrically coupled to the primaryconnector and is operative to provide an identification signal.

In accordance with another aspect, a USB adapter for providing a sourceof power to a mobile device through a USB port is provided. The USBadapter comprises a plug unit, a power converter, a primary USBconnector, and an identification subsystem. The plug unit is operativeto couple the USB adapter to a power socket and operative to receiveenergy from the power socket. The power converter is electricallycoupled to the plug unit and is operable to regulate the received energyfrom the power socket and to output a power requirement to the mobiledevice. The primary USB connector is electrically coupled to the powerconverter and is operative to couple to the mobile device and to deliverthe outputted power requirement to the mobile device. The identificationsubsystem is electrically coupled to the primary connector and isoperative to provide an identification signal.

Another aspect provides a USB adapter for providing a source of power toa mobile device through a USB port. The USB adapter comprises a plugunit, a power converter, a primary USB connector, and an auxiliary USBadapter. The plug unit is operative to couple the USB adapter to a powersocket and operative to receive energy from the power socket. The powerconverter is electrically coupled to the plug unit and is operable toregulate the received energy from the power socket and to output a powerrequirement to the mobile device. The primary USB connector iselectrically coupled to the power converter and is operative to coupleto the mobile device and to deliver the outputted power requirement tothe mobile device. The auxiliary USB connector has data lines that areelectrically coupled to the data lines of the primary USB connector.

Yet another aspect provides a method for providing energy to a mobiledevice using a USB adapter that comprises a plug unit, a primary USBconnector, a power converter electrically coupled between the plug unitand the primary USB connector, and an identification subsystemelectrically coupled to the primary USB connector. The method comprisingthe steps of coupling the USB connector to the mobile device, couplingthe plug unit to a power socket, outputting a power requirement to themobile device via the power converter and the USB connector, andproviding an identification signal to the mobile device, via theidentification subsystem and the USB connector, that is operative toinform the mobile device that the USB adapter is not limited by thepower limits imposed by the USB specification.

In accordance with another aspect, a powering system for a mobile devicehaving a USB connector is provided. The powering system comprises apower distribution subsystem in the mobile device that is operable toreceive energy through the USB connector and to distribute the energy toat least one component in the mobile device and a USB adapter that isoperative to couple to the USB connector. The USB adapter comprises aplug unit for coupling to a power socket and that is operable to receiveenergy from the power socket, a power converter electrically coupled tothe plug unit for regulating the received energy and for providing apower requirement to the power distribution subsystem, and anidentification subsystem that is operable to transmit an identificationsignal that is operative to identify the USB adapter as not beinglimited by the power limits imposed by the USB specification.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention identified in the claims may be more clearlyunderstood, preferred embodiments thereof will be described in detail byway of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of an exemplary mobile device which has anindustry standard interface;

FIG. 2 is a schematic diagram of a first embodiment of a USB adapterthat is coupled to an exemplary mobile device;

FIG. 3 is a flow chart illustrating an exemplary use of a USB adapterwith a mobile device; and

FIG. 4 is a schematic diagram of an additional exemplary embodiment of aUSB adapter that is coupled to both an exemplary mobile device and anexternal battery.

DETAILED DESCRIPTION Exemplary Mobile Device

Turning now to the drawing figures, shown in FIG. 1 is a schematicdiagram of an exemplary mobile communication device 10 which has anindustry standard interface. The mobile communication device 10 ispreferably a two-way communication device having at least voice or datacommunication capabilities. Preferably, the mobile device 10 is alsocapable of communicating over the Internet, for example, via a radiofrequency (“RF”) link. Examples of types of devices that could beclassified as a mobile device 10 include a data messaging device, atwo-way pager, a cellular telephone with data messaging capabilities, awireless Internet appliance, a data communication device (with orwithout telephony capabilities), a personal digital assistant (“PDA”), awireless two-way e-mail communication device, and others.

The exemplary mobile device 10 comprises a microprocessor 12, acommunication subsystem 14, input/output (“I/O”) devices 16, an industrystandard interface 18 which in this example is a USB port, and a powersubsystem 20. The microprocessor 12 controls the overall operation ofthe mobile device 10. The communication subsystem 14 provides the mobiledevice 10 with the ability to communicate wirelessly with externaldevices such as other mobile devices and other computers. The I/Odevices 16 provide the mobile device 10 with input/output capabilitiesfor use with a device user. The USB port 18 provides the mobile device10 with a serial port for linking directly with other computers and/or ameans for receiving power from an external power source. The powersubsystem 20 provides the mobile device 10 with a local power source.

The exemplary communication subsystem 14 comprises components such as areceiver 22, a transmitter 24, antenna elements 26 and 28, localoscillators (LOs) 30, and a processing module such as a digital signalprocessor (DSP) 32. The particular design of the communication subsystem14 and the components used therein can vary. It would be apparent to oneof ordinary skill in the art to design an appropriate communicationsubsystem using conventional methods and components to operate over acommunication network 34 based on the parameters necessary to operateover that communication network. For example, a mobile device 10geographically located in North America may include a communicationsubsystem 14 designed to operate within the Mobitex™ mobilecommunication system or DataTAC™ mobile communication system, whereas amobile device 10 intended for use in Europe may incorporate a GeneralPacket Radio Service (GPRS) communication subsystem 14.

Network access requirements will also vary depending upon the type ofnetwork 34. For example, in the Mobitex and DataTAC networks, mobiledevices 10 are registered on the network using a unique personalidentification number or PIN associated with each device. In GPRSnetworks however, network access is associated with a subscriber or userof a mobile device 10. A GPRS device therefore requires a subscriberidentity module (not shown), commonly referred to as a SIM card, inorder to operate on a GPRS network. Without a SIM card, a GPRS devicewill not be fully functional. Local or non-network communicationfunctions (if any) may be operable, but the mobile device 10 will beunable to carry out any functions involving communications over thenetwork 34.

When required, after the network registration or activation procedureshave been completed, a mobile device 10 may send and receivecommunication signals over the network 34. Signals received by thereceiver antenna 26 through a communication network 34 are input to thereceiver 22, which may perform such common receiver functions as signalamplification, frequency down conversion, filtering, channel selectionand the like, and in the exemplary system shown in FIG. 1, analog todigital conversion. Analog-to-digital conversion of a received signalallows more complex communication functions such as demodulation anddecoding to be performed in a DSP 32. Similarly, signals to betransmitted are processed, including modulation and encoding forexample, by the DSP 32 and input to the transmitter 24 fordigital-to-analog conversion, frequency up conversion, filtering,amplification and transmission over the communication network 34 via thetransmitter antenna 28.

Also, in the exemplary communication subsystem 14, the DSP 32 processescommunication signals and also provides for receiver and transmittercontrol. For example, the gains applied to communication signals in thereceiver 22 and transmitter 24 may be adaptively controlled throughautomatic gain control algorithms implemented in the DSP 32.

In implementing its control function, the microprocessor 12 in theexemplary mobile device 10 executes an operating system. The operatingsystem software used by the microprocessor 12 is preferably stored in apersistent store such as flash memory 36, or alternatively read onlymemory (ROM) or similar storage element. The microprocessor 12 may alsoenable the execution of specific device applications, which preferablyare also stored in a persistent store. The operating system, specificdevice applications, or parts thereof, may also be temporarily loadedinto a volatile store such as in RAM 38.

A predetermined set of applications which control basic deviceoperations, including at least data and voice communication applicationsfor example, will normally be installed on the mobile device 10 duringmanufacture. One such application loaded on the mobile device 10 couldbe a personal information manager (PIM) application. The PIM applicationpreferably is an application for organizing and managing user inputteddata items such as e-mail, calendar events, voice mails, appointments,and task items. The PIM data items may be stored in the RAM 38 and/orthe flash memory 36.

The PIM application preferably has the ability to send and receive dataitems, via the wireless network 34. The PIM data items are preferablyseamlessly integrated, synchronized and updated, via the wirelessnetwork 34, with corresponding data items stored or associated with ahost computer system (not shown) used by the device user. Thesynchronization of PIM data items is a process by which the PIM dataitems on the mobile device 10 and the PIM data items on the hostcomputer system can be made to mirror each other.

There are several possible mechanisms for loading applications onto themobile device 10. For example, applications may be loaded onto themobile device 10 through the wireless network 34, an auxiliary I/Osubsystem 40, the serial port 18, a short-range communications subsystem42, such as an infrared (“IR”) communication system, or any othersuitable subsystem 44. When loading the applications onto the mobiledevice 10, the device user may install the applications in the RAM 38,the flash memory 36, or preferably a non-volatile store (not shown) suchas ROM for execution by the microprocessor 12. The available applicationinstallation mechanisms can increase the utility of the mobile device 10by providing the device user with a way of upgrading the mobile device10 with additional and/or enhanced on-device functions,communication-related functions, or both. For example, a securecommunication application may be loaded onto the mobile device 10 thatallows for electronic commerce functions or other financial transactionsto be performed using the mobile device 10.

The I/O devices 16 may be used to display and/or compose datacommunication messages. In one mode of operation, a signal received bythe mobile device 10, such as a text message or web page download, willbe received and processed by the communication subsystem 14, forwardedto the microprocessor 12, which will preferably further process thereceived signal, and provide the processed signal to one or more of theI/O devices 16 such as a display 46. Alternatively, a received signalsuch as a voice signal can be provided to a speaker 48, or alternativelyto an auxiliary I/O device 40. In another mode of operation a deviceuser may compose a data item such as an e-mail message using a keyboard50 in cooperation with the display 46 and possibly an auxiliary I/Odevice 40. Alternatively, a device user may compose a voice message viaa microphone 52. The composed data item may then be transmitted over acommunication network 34 using the communication subsystem 14.

A short-range communications subsystem 42 may be provided in the mobiledevice 10 to allow the mobile device 10 to communicate with othersystems or devices, which need not necessarily be similar to device 10.For example, the short-range communications subsystem 42 may include aninfrared device and associated circuitry and components or a Bluetooth™communication module to allow the device 10 to communicate withsimilarly-enabled systems and devices.

The USB port 18 provides the mobile device 10 with a serial port forlinking directly with other computers to exchange data and/or to receivepower. The USB port 18 also provides the mobile device 10 with a meansfor receiving power from an external power source. For example, in apersonal digital assistant (PDA)-type communication device, the USB port18 could be used to allow the mobile device 10 to synchronize data witha user's desktop computer (not shown). The USB port 18 could also enablea user to set parameters in the mobile device 10 such as preferencesthrough the use of an external device or software application. Inaddition the USB port 18 may also be used to provide a means fordownloading information or software to the mobile device 10 withoutusing the wireless communication network 34. The USB port 18 can providea direct and thus reliable and trusted connection that may for examplebe used to load an encryption key onto the mobile device 10 therebyenabling secure device communication.

Coupled to the USB port 18 is a USB connector 54. The USB connector 54is the physical component that couples the USB port 18 to the outsideworld. In the exemplary mobile device 10, the USB connector 54 is usedto transmit and receive data from an external data/power source 56,receive power from the external data/power source 56, direct thetransmitted/received data from/to the USB port 18, and direct thereceived power to the power subsystem 20.

The exemplary power subsystem 20 comprises a charging and powerdistribution subsystem 58 and a battery 60. The charging and powerdistribution subsystem 58 performs many functions. It may be used totransfer energy to the battery 60 from the external data/power source 56to charge the battery 60 and also to distribute power to the manypower-requiring components within the mobile device 10. The chargingsubsystem 58 may be capable of determining the presence of a battery 60and/or a power circuit coupled to the mobile device 10, such as an ACadapter, USB connection, or car adapter, which alternatively can act aspower sources 56 to provide power for the mobile device 10 and to chargethe battery 60. Additionally, the charging subsystem 58 may have theability to determine if a power source 56 is coupled to the mobiledevice 10 and, in the absence of such a coupling, cause the mobiledevice 10 to be powered by the battery 60.

The power distributed by the charging and power distribution subsystem58 may be derived from energy stored in the battery 60 and/or energyreceived from the external data/power source 56. When the battery 60 isdepleted, the charging and power distribution subsystem 58 transfersenergy from the power source 56 to recharge the battery 60. Optionally,the charging and power distribution subsystem 58 may also transferenergy from the power source 56 to other components in the mobile device10 to power the mobile device 10 when the battery 60 has been depletedand is recharging. When the data/power source 56 is not connected to themobile device 10, power for the device 10 is derived from the battery60.

Exemplary USB Adapter

FIG. 2 is a schematic diagram of a first embodiment of an adapter 100that can be used to couple the mobile device 10 of FIG. 1 to thedata/power source 56 of FIG. 1. In this example the adapter 100 is a USBadapter 100 that comprises a primary USB connector 102, a powerconverter 104, a plug unit 106, and an identification subsystem 108. Thepower converter is a known element in the art and typically includes atleast one of the following components: switching converter, transformer,DC source, voltage regulator, linear regulator and rectifier. In theembodiment shown in FIG. 2, the USB adapter 100 is shown coupling amobile device 10 to one of one or more types of power sockets 110N,110D, 110B, and 110. Also shown in FIG. 2 is an optional auxiliary USBconnector 112 that can be used to couple the mobile device 10 to a datasource (not shown) such as a personal computer.

In the embodiment shown in FIG. 2, the primary USB connector 102 isconfigured to mate with the USB connector 54 of the mobile device 10.The USB adapter 100 is operable to provide power to the mobile device 10through the Vbus and Gnd power pins in the USB connectors 54 and 102.The USB adapter 100 also optionally provides a communication path fordata across the D+ and D− data pins in the USB connectors 54 and 102.

The plug unit 106 is preferably a conventional plug unit that can beused to couple with a conventional power socket to receive powertherefrom. For example, the plug unit 106 can be a two-prong orthree-prong plug of the type used in North America that can couple to aNorth American AC power socket 110N that provides 115 VAC. In theembodiment shown in FIG. 2, the plug unit 106 can accept one or moretypes of plug adapters 114N, 114B, 114D, and 114 that are configured tocouple to the plug unit 106 and are further configured to directly matewith one or more types of power sockets 110N, 110D, 110B, and 110. Theplug unit 106 can be configured to receive energy from a power socket110N, 110D, 110B, or 110, either directly or through the use of a plugadapter, and is operative to transfer the received energy to the powerconverter 104.

The power converter 104 is operative to receive energy from a powersocket 110N, 110D, 110B, or 110 and to convert that received energy to aform that can be used by the mobile device 10. For example, the powerconverter 104 can be of conventional construction such as a switchingpower converter that converts 115 VAC to 5 VDC. Also, the powerconverter 104 could comprise a D.C. regulator circuit that converts aD.C. input to a D.C. output. The power converter 104 could also beadapted to accept a wide range of input energy levels and frequencies.Alternatively, the power converter 104 could be adapted to accept alimited range of input energy levels and frequencies, wherein the plugadapters are operable to convert the possible input energy levels andfrequencies to a range that the power converter 104 can accommodate. Thepower converter 104 provides its energy output to the mobile device 10via the Vbus and Gnd pins of the primary USB connector 102.

Through the use of a variety of different types of plug adapters, theUSB adapter 100 can be adapted to receive energy from various types ofpower sockets 110N, 110D, 110B, or 110. For example, using theappropriate plug adapter 114, 114B, 114D, and 114N, the USB adapter 100can receive energy from a power socket such as a 115 VAC North Americanpower socket 110N, or a 12 VDC automobile power socket, or an air powersocket, or others.

For example, in North America, a type “N” power socket is commonlyavailable. The plug adapter 114N can be releasably attached to the plugunit 106 thereby allowing any North American power socket 114N to beused as a power source. When traveling to a locale which does not havethe North American power socket 114N, an alternate plug adapter such asadapters 114, 114B, or 114D may be selected by the user, according tothe power socket 110D, 110B, or 110 available at the locale. The plugadapter 114, 114B, or 114D may then be releasably attached to plug unit106 in place of the plug adapter 114N, thereby allowing the USB poweradapter 100 to connect to a local power supply via the local powersocket. Various other plug adapters are envisioned that can beconfigured to operate with alternate power sources such as for instancecar sockets.

The power distribution and charging subsystem 58 of the mobile device 10can selectively use the power provided on the Vbus and Gnd lines of theUSB connector 54 to provide power to the mobile device 10, charge thebattery 60, or both. A more detailed discussion of how the chargingfunction of mobile device 10 can be implemented is described in U.S.Provisional Application No. 60/273,021 filed on Mar. 1^(st), 2001 andentitled “System and Method for Adapting a USB to Provide Power forCharging a Mobile Device” which has been incorporated herein byreference.

Typically when a mobile device 10 receives power over the USB from a USBhost, it is required to draw power in accordance with the USBspecification. The USB specification specifies a process fortransferring energy across the USB called enumeration and limits theelectrical current that can flow across the USB.

The USB adapter 100 contributes to a system wherein a device 10 thatfollows the USB specification when coupled to a typical USB host via itsUSB port can be informed that the USB adapter 100 has been coupled tothe device 10 and that the device 10 can now draw power without regardto the USB specification and the USB specification imposed limits.

The identification subsystem 108 provides an identification signal tothe mobile device 10 that the power source is not a USB limited source.The identification signal could be the communication of a single voltageon one or more of the USB data lines, different voltages on the two datalines, a series of pulses or voltage level changes, or other types ofelectrical signals. The identification subsystem 108 that generates theidentification signal could have multiple types of configurations. Inone embodiment, the identification subsystem 108 comprises a hard-wiredconnection of a single voltage level to both data lines. In anotherembodiment, the identification subsystem 108 comprises a USB controllerthat is operable to communicate an identification signal to the mobiledevice 10. Additional embodiments are contemplated. The identificationsubsystem 108 may optionally be configured to have the capability ofelectrically connecting or disconnecting the power output from the powerconverter 104 from the USB connector 102 and/or to connect or disconnectany data inputs from the USB adapter 100 to the USB connector 102.

In addition to providing power to the mobile device 10 over the primaryUSB connector 102, the USB adapter 100 may optionally be equipped withan auxiliary USB connector 112 that allows the USB adapter 100 to createa communication path between the mobile device 10 and some other devicecapable of communicating over the USB such as a personal computer,another mobile device or some other type of device.

The USB adapter 100 preferably provides a communication path between theD+ and D− pins of the Primary USB connector 102 and the D+ and D− pinsof the auxiliary USB connector 112. In the embodiment shown, thecommunication path also traverses the identification subsystem 108.Alternatively, the communication path could bypass the identificationsubsystem 108. The USB adapter 100 can thus act as a pass-through devicefor communication between a USB hub or host and a mobile device 10.

Optionally, the USB adapter 100 could also transfer energy from thepower converter 104 to the auxiliary USB connector 112 thereby providinga device coupled to the auxiliary USB connector 112 with power. In thisarrangement, the identification subsystem 108 could also provide anidentification signal to the device coupled to the auxiliary USBconnector 112 to inform that device that the power source is not a USBlimited source.

Exemplary Illustration of the Use of a USB Adapter with a Mobile Device

When a USB adapter 100 is connected to a mobile device 10, theidentification subsystem 108 of the USB adapter 100 preferably providesan identification signal to the mobile device 10 to notify the mobiledevice 10 that the device 10 is connected to a power source that is notsubject to the power limits imposed by the USB specification.Preferably, the mobile device 10 is programmed to recognize theidentification signal and therefore recognizes that an identificationsignal has been transmitted by the USB adapter 100. After recognizing avalid identification signal, the mobile device 10 draws power throughthe USB adapter 100 without waiting for enumeration or chargenegotiation.

The detection of the identification signal may be accomplished using avariety of methods. For example, the microprocessor 12 may detect theidentification signal by detecting the presence of an abnormal data linecondition at the USB port 18. The detection may also be accomplishedthrough the use of other device subsystems 44 in the mobile device 10.The preferred identification signal results from the application ofvoltage signals greater than 2 volts to both the D+ and D− lines in theUSB connector 54. The preferred method of identification is describedbelow in greater detail with reference to FIG. 3.

At step 210, the mobile device 10 detects the presence of a voltage onthe Vbus line of the USB connector 54 via the USB port 18. At step 220,the mobile device checks the state of the D+ and D− lines are comparedto a 2V reference. Also, in this example, the identification subsystem108 of the USB adapter 100 may have applied a logic high signal, such as+5V reference, to both the D+ and D− lines to identify the attacheddevice as a USB adapter 100. If the voltages on both the D+ and D− linesof the USB connector are greater than 2 Volts (step 220), then themobile device 10 determines that the device connected to the USBconnector 54 is not a typical USB host or hub and that a USB adapter 100has been detected (step 230). The mobile device 10 can then charge thebattery or otherwise use power provided via the Vbus and Gnd lines inthe USB connector 54 (step 260) without waiting for enumeration.

If, however, after the mobile device 10 detects the presence of avoltage on the Vbus line of the USB connector 54 and determines that thevoltages on both the D+ and D− lines of the USB connector 54 are notgreater than 2 Volts (step 220), then the mobile device 10 determinesthat a USB host or hub has been detected (step 240). A typical USB hostor hub weakly holds its D+ and D− lines at zero volts when it is notconnected to another device. The mobile device 10 can then signal theUSB host or hub to initiate the enumeration process (step 250) and cancharge the battery or otherwise use power provided via the Vbus and Gndlines in the USB connector 54 (step 260) in accordance with the powerlimits imposed by the USB specification. The enumeration process istypically initiated after the mobile device 10 applies approximatelyzero volts to the D− line and approximately 5 volts to the D+ line toinform the host of the mobile device's 10 presence and communicationspeed.

Therefore, when a USB adapter 100 is coupled to the mobile device 10 andhas been identified as a USB adapter 100, the mobile device 10 canforego the enumeration process and charge negotiation process andimmediately draw energy from the USB power adapter 100 at a desiredrate, for instance at 5 unit loads, i.e. 500 mA. While the mobile device10 charges its battery using the USB adapter 100, the mobile device 10can disable its typical USB functions. If, however, the mobile device 10detects that a USB host or hub is coupled to the mobile device 10, themobile device 10 can apply a voltage to the D+ line to indicate to theUSB host or hub that the mobile device 10 is coupled thereto and awaitenumeration and USB charge negotiation.

If the USB adapter 100 is coupled to the mobile device 10, and themobile device 10 does not identify the USB adapter 100 throughcommunications with the identification module 108, the mobile device 10may stop drawing energy from the Vbus and Gnd lines of the USB connector54. This may occur, for example, if the mobile device 10 is notprogrammed to identify the USB adapter 100. The mobile device 10 maymistakenly identify the USB adapter 100 as a typical USB host or hub andawait enumeration before drawing substantial energy. To guard againstthis, the USB adapter 100 can optionally be adapted to function withmobile devices that are not programmed to recognize the USB adapter 100.

In that scenario, the USB adapter 100 can be adapted to provide energyto a mobile device by using the knowledge that the mobile device willdraw energy from a connected device for a period of time before it stopsdrawing energy due to lack of enumeration. The USB adapter 100 canoptionally provide power for charging a battery 60 in a mobile device byperiodically switching the voltages on the Vbus and Gnd lines between onand off states. When the USB adapter 100 is coupled to the mobiledevice, the identification subsystem 108 can apply an on-voltage (5 Vfor example) between the Vbus and Gnd lines. The mobile device will drawenergy while awaiting enumeration. After a period of time, theidentification subsystem 108 can apply an off-voltage (0 volts) betweenthe Vbus and Gnd lines thereby fooling the mobile device intodetermining that the unidentified USB device has been disconnected fromthe mobile device. The identification subsystem 108 can then reapply anon-voltage between the Vbus and Gnd lines. The mobile device will drawenergy again while awaiting enumeration. This cycle can be repeated toperiodically apply energy to the mobile device, for example, to rechargethe battery 60 of the mobile device.

Additional Exemplary Embodiments of USB Adapters

Shown in FIG. 4 is a schematic diagram of an additional exemplaryembodiment of a USB adapter 300 that is coupled to a mobile device 10.The exemplary USB adapter 300 comprises a USB connector 302, a powerconverter 304, a plug unit 306, and an identification subsystem 308. TheUSB connector 302, plug unit 306, and identification subsystem 308preferably correspond to the USB connector 102, plug unit 106, andidentification subsystem 108 which were described earlier with respectto the first embodiment. Similar to the first embodiment, the additionalembodiment may optionally be equipped with various plug adapters 314N,314D, 314B, and 314 that preferably are releasably attachable to plugunit 306 so that the appropriate plug adapter 314N, 314D, 314B, or 314can be selected by a user to allow the USB adapter 300 to couple to andreceive energy from an available power socket 310N, 310D, 310B, or 310.The exemplary USB power converter 300 further comprises a chargingsubsystem 316 and battery receptacle 318 for coupling the USB adapter300 to an external battery 320 that may be optionally coupled thereto.

The battery receptacle 318 provides a location for releasably couplingan external battery 320 thereto so that the external battery can becharged via the USB adapter 300. This provides the USB adapter 300 witha mechanism for charging, for example, a mobile device's primary orspare battery when the battery has been separated from or is not coupledto the mobile device 10.

To accommodate this functionality, the power converter 304 is capable ofproviding the proper voltage levels for the USB connector 302 and alsocapable of providing necessary voltage and current levels to drive abattery charging subsystem 316. The power converter 304 is preferably adual power converter that may be constructed using conventional ornon-conventional architectures. With respect to the portion of the powerconverter 304 that provides energy to the USB connector 302, thatportion is preferably similar in construction and function to the powerconverter 104 of the first embodiment.

Preferably, the charging subsystem 316 performs in a substantiallysimilar manner to charging subsystem 58 of the mobile device 10. But,for efficiency and simplicity of design, certain aspects of the dualpower converter 304 and the charging subsystem 316 may be combined, asboth are local to the USB adapter 300.

Other alternative embodiments of the USB adapter may include variouscombinations of components described above with respect to the first andadditional embodiments. Another embodiment of the USB adapter mayinclude a second or more auxiliary USB connectors. A USB adapter havingone or more auxiliary USB connectors may optionally be configured suchthat one or more of the auxiliary USB connectors may have power from theUSB adapter's power converter made available to it so that multiple USBdevices may draw power simultaneously. Preferably, a USB adapter havingmultiple auxiliary USB connectors will be configured such that the datalines in the auxiliary connectors can, on a selective basis, beelectrically connected to or disconnected from the data lines in theprimary USB connector. This allows a mobile device connected to theprimary USB connector to receive energy from the adapter regardless ofwhether a USB host or hub is connected to an auxiliary USB connector. Itis also contemplated that a USB adapter may be embodied in a USB host orhub.

CONCLUSION

The embodiments described herein are examples of structures, systems ormethods having elements corresponding to the elements of the inventionrecited in the claims. This written description may enable those skilledin the art to make and use embodiments having alternative elements thatlikewise correspond to the elements of the invention recited in theclaims. The intended scope of the invention thus includes otherstructures, systems or methods that do not differ from the literallanguage of the claims, and further includes other structures, systemsor methods with insubstantial differences from the literal language ofthe claims. Although the embodiments have been described with referenceto the USB interface, it is contemplated that the invention could beapplicable to devices and systems that use other standard interfacessuch as the IEEE 1394 interface.

1. A mobile device, comprising: a USB communication path; and a chargingsubsystem enabled to draw current unrestricted by at least onepredetermined USB Specification limit, said enablement being responsiveto an abnormal USB data condition detected at said USB communicationpath.
 2. The device of claim 1, wherein said predetermined USBSpecification limit is a current limit.
 3. The device of claim 1,wherein said enabling of the charging subsystem occurs without USBenumeration.
 4. The device of claim 1, wherein said USB communicationpath includes a D+ line and a D− line.
 5. The device of claim 4, whereinsaid abnormal USB data condition is an abnormal USB data line conditionon said D+ line and said D− line.
 6. The device of claim 5, wherein saidabnormal USB data line condition is a logic high signal on each of saidD+ and D− lines.
 7. The device of claim 1, wherein said predeterminedUSB Specification limit is a current limit of 500 mA.
 8. The device ofclaim 6, wherein each said logic high signals is signals greater than2V.
 9. A mobile device, comprising: a USB communication path and a USBVBUS line; and a charging subsystem enabled to draw power unrestrictedby at least one predetermined USB Specification limit, said enablementbeing responsive to said USB VBUS line being externally powered and anabnormal USB data condition detected at said USB communication path. 10.The device of claim 9, wherein said predetermined USB Specificationlimit is a current limit defined by USB Specification.
 11. The device ofclaim 9, wherein said enabling of the charging system occurs without USBenumeration.
 12. The device of claim 9, wherein said USB communicationpath includes a D+ line and a D− line.
 13. The device of claim 12,wherein said abnormal USB data condition is an abnormal USB data linecondition on said D+ line and said D− line.
 14. The device of claim 13,wherein said abnormal USB data line condition is a logic high signal oneach of said D+ and D− lines.
 15. The device of claim 9, wherein saidpredetermined USB Specification limit is a current limit of 500 mA. 16.The device of claim 13, wherein each said logic high signals is signalsgreater than 2V.
 17. A method of charging a mobile device having acharging subsystem and a USB communication path, comprising: upondetection of an identification signal on said path, drawing current inexcess of at least one USB Specification defined limit; and if saididentification signal is not detected, drawing current in accordancewith said USB Specification.
 18. The method of claim 17, wherein saidUSB Specification defined limit is a current limit defined by USBSpecification.
 19. The method of claim 17, wherein the identificationsignal includes an abnormal signal on the USB communication path. 20.The method of claim 19, wherein said USB communication path includes aD+ line and a D− line.
 21. The method of claim 20, wherein the abnormalsignal includes logic high signals on said D+ line and said D− line. 22.The method of claim 18, wherein said current limit is a current limit of500 mA.
 23. The method of claim 20, wherein said logic high signals aresignals greater than 2V.
 24. A mobile device, comprising: a USBcommunication path including a D+ line and a D− line; and a chargingsubsystem enabled to draw current in excess of 500 mA, said enablementbeing responsive to signals in excess of 2V detected at each of said D+and D− lines and said enablement occurring without USB enumeration.